This invention relates generally to slide fasteners, and in particular to the construction of a novel emergency opening slider which can be mounted in any selected position on interlocked rows of fastener elements or scoops and which, in the event of a fire or other emergencies, permits the fastener to be forced open from the selected position without resort to the use of the usual slider. The slide fastener of this character can be employed on entrances of camping tents and like articles to the best advantage.
There has been known a slide fastener with an emergency opening zone at its intermediate point where the rows of fastener elements are made incapable of interlocking engagement when the fastener is closed, in order that the fastener stringers may be manually spread apart from the zone in an emergency. The emergency opening zone is a predetermined zone where several fastener elements on each stringer tape are usually nonexistent. For the manufacture of the conventional slide fasteners with the emergency openable function, therefore, it it necessary to remove the several fastener elements from the completed stringers, or to form the stringers in which the unnecessary elements have not been attached to the tapes.
In either case the position of the emergency opening zone on the completed slide fasteners is not adjustable according to the specific applications or working conditions of the fasteners. For this reason the slide fastener manufacturers have heretofore been required to produce and keep in stock various types of fastener stringers having the emergency opening zones formed in different positions thereon. This practice necessitates high manufacturing and storage costs and renders the product management highly troublesome.